Slip rate and tremor genesis in Cascadia

TitleSlip rate and tremor genesis in Cascadia
Publication TypeJournal Article
Year of Publication2014
AuthorsWech A.G, Bartlow N.M
JournalGeophysical Research Letters
Volume41
Pagination392-398
Date Published2014/01
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000332991000028
KeywordsCascadia; continuum; episodic; episodic tremor and slip; events; japan; slip rate; slow earthquakes; slow slip; subduction zone; subduction zones; tectonic tremor; tohoku-oki earthquake; tremor
Abstract

At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip. Key Points Slip speed regulates tremor Same event and same fault can slip with and without detected tremor Fault segmentation inhibits slow slip propagation

DOI10.1002/2013gl058607
Integrated Research Themes: 
Student Publication: 
No